mac80211: fix virtual interfaces vs. injection

Currently, virtual interface pointers passed to drivers might be
from monitor interfaces and as such completely uninitialised
because we do not tell the driver about monitor interfaces when
those are created. Instead of passing them, we should therefore
indicate to the driver that there is no information; do that by
passing a NULL value and adjust drivers to cope with it.

As a result, some mac80211 API functions also need to cope with
a NULL vif pointer so drivers can still call them unconditionally.

Also, when injecting frames we really don't want to pass NULL all
the time, if we know we are the source address of a frame and have
a local interface for that address, we can to use that interface.
This also helps with processing the frame correctly for that
interface which will help the 802.11w implementation. It's not
entirely correct for VLANs or WDS interfaces because there the MAC
address isn't unique, but it's already a lot better than what we
do now.

Finally, when injecting without a matching local interface, don't
assign sequence numbers at all.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 25 insertions, 12 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 6eb222369bcb..f32561ec224c 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -231,16 +231,21 @@ __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
 					struct ieee80211_rate *rate)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
-	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+	struct ieee80211_sub_if_data *sdata;
 	u16 dur;
 	int erp;
+	bool short_preamble = false;
 
 	erp = 0;
-	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
-		erp = rate->flags & IEEE80211_RATE_ERP_G;
+	if (vif) {
+		sdata = vif_to_sdata(vif);
+		short_preamble = sdata->bss_conf.use_short_preamble;
+		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
+			erp = rate->flags & IEEE80211_RATE_ERP_G;
+	}
 
 	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
-				       sdata->bss_conf.use_short_preamble);
+				       short_preamble);
 
 	return cpu_to_le16(dur);
 }
@@ -252,7 +257,7 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_rate *rate;
-	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
 	int erp;
 	u16 dur;
@@ -260,13 +265,17 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
 
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 
-	short_preamble = sdata->bss_conf.use_short_preamble;
+	short_preamble = false;
 
 	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
 
 	erp = 0;
-	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
-		erp = rate->flags & IEEE80211_RATE_ERP_G;
+	if (vif) {
+		sdata = vif_to_sdata(vif);
+		short_preamble = sdata->bss_conf.use_short_preamble;
+		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
+			erp = rate->flags & IEEE80211_RATE_ERP_G;
+	}
 
 	/* CTS duration */
 	dur = ieee80211_frame_duration(local, 10, rate->bitrate,
@@ -289,7 +298,7 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_rate *rate;
-	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+	struct ieee80211_sub_if_data *sdata;
 	bool short_preamble;
 	int erp;
 	u16 dur;
@@ -297,12 +306,16 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
 
 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 
-	short_preamble = sdata->bss_conf.use_short_preamble;
+	short_preamble = false;
 
 	rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
 	erp = 0;
-	if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
-		erp = rate->flags & IEEE80211_RATE_ERP_G;
+	if (vif) {
+		sdata = vif_to_sdata(vif);
+		short_preamble = sdata->bss_conf.use_short_preamble;
+		if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
+			erp = rate->flags & IEEE80211_RATE_ERP_G;
+	}
 
 	/* Data frame duration */
 	dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,